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Objectives Monitoring quality indicators (QIs) is an important part of laboratory quality assurance (QA). Here, the Canadian Society of Clinical Chemists (CSCC) Point of Care Testing (POCT) and QI Special Interest Groups describe a process for establishing and monitoring QIs for POCT glucose testing. Methods Key, error prone steps in the POCT glucose testing process were collaboratively mapped out, followed by risk assessment for each step. Steps with the highest risk and ability to detect a non-conformance were chosen for follow-up. These were positive patient identification (PPID) and repeat of critically high glucose measurements. Participating sites were asked to submit aggregate data for these indicators from their site(s) for a one-month period. The PPID QI was also included as part of a national QI monitoring program for which fifty-seven sites submitted data. Results The percentage of POCT glucose tests performed without valid PPID ranged from 0–87%. Sites without Admission-Discharge-Transfer (ADT) connectivity to POCT meters were among those with the highest percentage of POCT glucose tests performed without valid PPID. The percentage repeated critically high glucose measurements ranged from 0–50%, indicating low compliance with this recommendation. A high rate of discordance was also noted when critically high POCT glucose measurements were repeated, demonstrating the importance of repeat testing prior to insulin administration. Conclusions Here, a process for establishing these QIs is described, with preliminary data for two QIs chosen from this process. The findings demonstrate the importance of QIs for identification and comparative performance monitoring of non-conformances to improve POCT quality.

Objectives Free light chain (FLC) is used for the diagnosis and prediction with regard to the progression risk of plasma cell disorders and Freelite reagent using the SPAplus analyzer (The Binding Site) has been one of the widely used option. However, N Latex FLC reagent with the Atellica CH 930 analyzer (Siemens Healthineers) has shown the advantages of automation and high throughput. We aimed to evaluated clinical implication by differential analytical performances of two assays. Methods A total of 322 serum samples were collected from 193 patients requested for FLC analysis including 131 multiple myeloma patients. The precision, linearity, dilution recovery of N Latex FLC assay was evaluated. We compared the two assays and analyzed the monomer-dimer pattern for discrepant results. Results The precision, linearity, and dilution recovery performance was appropriate for the routine use in clinical laboratories. Despite the good correlation within normal range, proportional bias up-to 170% was observed in samples with high concentrations especially for lambda. The higher value samples with N Latex FLC assay contained more monomer forms than controls. All opposite changes of FLC burden by the N Latex FLC assay proved to present concordant dynamic changes when assessed by serum protein electrophoresis. Conclusions Clinical laboratories should be aware of the inter-assay variability of FLC quantitative measurements using different platforms, especially for high concentrations of both kappa and lambda measurements, possibly due to monomer/dimer ratio diversity. Clinical interpretations for multiple myeloma disease status might not be dramatically affected only when the same assay is utilized during follow-up periods.

Objectives The study aimed to evaluate dual liquid chromatography (LC) coupled to high-resolution mass spectrometry (HRMS) for the simultaneous analysis of small and large molecule drugs by development and application of a validated bioanalytical method. Methods The oral antihyperglycemic drugs (OAD) dapagliflozin, empagliflozin, glibenclamide, glimepiride, metformin, pioglitazone, repaglinide, saxagliptin, sitagliptin, and vildagliptin, as well as the antihyperglycemic peptides exenatide, human insulin, insulin aspart, insulin degludec, insulin detemir, insulin glargine, insulin glulisine, insulin lispro, and semaglutide were included in the analytical procedure. Analytes were extracted using a combination of protein precipitation and solid-phase extraction. Two identical reversed-phase columns were used for separation followed by Orbitrap high-resolution mass spectrometry. The whole procedure was validated according to international recommendations. Results Different MS parameters had to be used for the two analyte groups, but dual LC separation allowed elution of all analytes within 12 min using the same column type. The analytical procedure was accurate and precise for most of the compounds except for exenatide, semaglutide, and insulin glargine, which were included qualitatively in the method. Analysis of proof-of-concept samples revealed OAD concentrations mostly within their therapeutic range, insulins could be detected in five cases but at concentrations below the lower limit of quantification except for one case. Conclusions Dual LC in combination with HRMS was shown to be a suitable platform to analyze small and large molecules in parallel and the current method allowed the determination of a total of 19 antihyperglycemic drugs in blood plasma within 12 min.

Objectives Because acute myocardial infarction (AMI) may occur suddenly and cannot be predicted, it is critical to identify early diagnosis markers. In recent years, in addition to the developing diagnostic methods, other markers that may be related to the diagnosis of AMI are miRNA molecules. The specificity of miRNAs involved in the pathogenesis of atherosclerosis and regulation of cardiac functions has been shown. The present study aimed to investigate the changes in miRNA expression levels in MI patients with ST-elevation (STEMI) and without ST elevation (NSTEMI). Methods In this study, 25 patients with STEMI, 25 with NSTEMI, and 20 healthy participants were included. Expression analysis of miRNAs isolated from the plasma of individuals was performed using high-throughput real-time PCR. Results Compared with the control group, miR-221-3p and miR-30d-5p were downregulated, while miR-25-3p, miR-92a-3p, miR-34a-5p and miR-150 upregulated in the patient group with NSTEMI; miR-221-3p, miR-25-3p, miR-30d-5p and miR-92a-3p were downregulated while miR-208a-3p was upregulated in patients with STEMI (p>0.05). Conclusions In conclusion, miRNAs may be an early biomarker for diagnosing AMI; however, further and larger studies are needed.

Objectives Antinuclear antibodies (ANA) are important for the diagnosis of various autoimmune diseases. ANA are usually detected by indirect immunofluorescence assay (IFA) using HEp-2 cells (HEp-2 IFA). There are many variables influencing HEp-2 IFA results, such as subjective visual reading, serum screening dilution, substrate manufacturing, microscope components and conjugate. Newer developments on ANA testing that offer novel features adopted by some clinical laboratories include automated computer-assisted diagnosis (CAD) systems and solid phase assays (SPA). Methods A group of experts reviewed current literature and established recommendations on methodological aspects of ANA testing. This process was supported by a two round Delphi exercise. International expert groups that participated in this initiative included (i) the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group “Autoimmunity Testing”; (ii) the European Autoimmune Standardization Initiative (EASI); and (iii) the International Consensus on ANA Patterns (ICAP). Results In total, 35 recommendations/statements related to (i) ANA testing and reporting by HEp-2 IFA; (ii) HEp-2 IFA methodological aspects including substrate/conjugate selection and the application of CAD systems; (iii) quality assurance; (iv) HEp-2 IFA validation/verification approaches and (v) SPA were formulated. Globally, 95% of all submitted scores in the final Delphi round were above 6 (moderately agree, agree or strongly agree) and 85% above 7 (agree and strongly agree), indicating strong international support for the proposed recommendations. Conclusions These recommendations are an important step to achieve high quality ANA testing.

Objectives Biobanked samples are becoming increasingly important for research outcomes. Most of the biobanking processes (from preparation to storage) are affected by temperature in a time-dependent manner and have a high impact on sample quality. We aimed to validate time and temperature sensitive processes such as sample preparation, transport, sorting, and storage, which have a high impact on sample quality. Methods Temperature was measured using internal or external temperature data loggers. We analysed the temperature and present real data from our sample transport on dry ice and with the CryoPod, from our ultra-low temperature freezers (UTFs) of different manufacturers and cryostores. We also tested sample sorting on dry ice and in a cryogenic workbench. Results In the UTFs, we identified temperature zones with a temperature difference from 4.7 °C up to 20.8 °C across the whole UTF. For sample transport within approximately 30 min we observed temperatures of −80.2 °C ± 4.0 °C and −173.9 °C ± 16.9 °C for dry ice boxes and the CryoPod, respectively. Sorting on dry ice was best in a polystyrene box half-filled with dry ice pellets, although the temperature increased by 7.5 °C within the first 5 min, whereas the temperature in the cryogenic workbench remained stable below −100 °C for hours. Conclusions Time and temperature play a crucial role in the entire biobanking process, with sometimes immense temperature fluctuations in some equipment. We recommend the validation or verification of all equipment and processes used to avoid pre-analytical errors in accordance with DIN EN ISO 20387.

Objectives Routine blood examination, one of the most commonly performed tests in clinical laboratories, directly reflects the overall state of the body such as inflammation, anemia, and thrombocytopenia. The accuracy of these indicators by tests may be perturbed by various factors including anticoagulants, antibodies, and temperatures. Pseudoleukopenia caused by leukoagglutination was rarely described in the literature. Case presentation We report a rare and unusual pseudo-leukopenia case of a 75-year-old female with a stroke. Blood samples from the patient were collected using different anticoagulants and determined the hematologic parameters and blood smears. We observed the extent of leukocyte aggregation at different anticoagulants or temperatures. The intensity of leukoagglutination was attenuated after incubating at 37 °C for 30 min. After anti-infection treatment and symptomatic treatment, the leukoagglutination of the patient gradually weakened. Conclusions We have found the reason for the pseudo-leukopenia and the leukocyte aggregation phenomenon may vary with disease progression.

In May 2022, the European Regulation 2017/746 (IVDR) came into force. It changes the approach of in vitro medical devices (IVD-MDs) for industry and institutions. It reinforces the clinical evidence requirements to improve performance, safety and transparency. Despite extended transition periods and existing guides, IVDR remains difficult to interpret and bringing devices into compliance requires efforts. The generation of clinical evidence is essential to demonstrate compliance with IVDR, and encompasses scientific validity, analytical performance and clinical performance. It is required to demonstrate, per intended use in the target population and clinical care pathway, IVD-MDs clinical performance (compared to a predefined clinical performance). Thus, there is a need for IVD-manufacturers and end-users in health care institutions, to obtain guidance on how to generate this clinical evidence. This article aims industrials and clinicians to identify key steps imposed by the IVDR for bringing IVD-MDs to the EU-market. We propose a general view of performance evaluation requirements for IVD-MDs and provide key references, including how to establish study design that will enable to document clinical performance of existing, refined or emerging medical tests. Finally, we propose a roadmap to address the relevant questions and studies in relation to the documents requested in the IVDR.

Neurobiomarkers have attracted significant attention over the last ten years. One promising biomarker is the neurofilament light chain protein (NfL). Since the introduction of ultrasensitive assays, NfL has been developed into a widely used axonal damage marker of relevance to the diagnosis, prognostication, follow-up, and treatment monitoring of a range of neurological disorders, including multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer’s disease. The marker is increasingly used clinically, as well as in clinical trials. Even if we have validated precise, sensitive, and specific assays for NfL quantification in both cerebrospinal fluid and blood, there are analytical, as well as pre- and post-analytical aspects of the total NfL testing process, including biomarker interpretation, to consider. Although the biomarker is already in use in specialised clinical laboratory settings, a more general use requires some further work. In this review, we provide brief basic information and opinions on NfL as a biomarker of axonal injury in neurological diseases and pinpoint additional work needed to facilitate biomarker implementation in clinical practice.

Objectives Our aim in this study was to examine the effects of different anti-inflammatory treatment strategies on the process of atherosclerosis, which is an important cause of mortality in ankylosing spondylitis (AS) patients, by examining the possible effect of treatments on inflammation, lipid profile and oxidative stress parameters in patients with AS. Methods In this study, 32 healthy volunteers served as the control group in addition to a total of 76 AS patients who were divided into two groups according to whether they were receiving anti-TNF medications or not. We assessed the levels of inflammation, oxidative stress, lipid profile parameters, and oxidized low-density lipoprotein (oxLDL). The atherogenic index of plasma (AIP), non-HDL cholesterol levels, BASDAI, and BASFI scores were also calculated. Results AS patient groups and the control group had similar lipid profile parameters, thiol-disulfide homeostasis metrics, non-HDL cholesterol, oxLDL, and AIP levels (p>0.05). In contrast to AS patients receiving non-anti-TNF treatment, the BASDAI and BASFI scores, ESR, and CRP levels were lower in AS patients receiving anti-TNF treatment (p Conclusions AS patients face increased oxidative stress that does not correlate with inflammatory status and disease activation level. Anti-TNF alpha treatment may reduce some risk factors of atherosclerotic CVD in AS patients.

Objectives Lysosomal dysfunction could lead to a failure in the degradation process of waste materials, especially for the elimination of aggregated, misfolded and senescence proteins or organelles. Human brain endothelial cells (HBECs) are a part of the blood-brain barrier and any disruption of lysosomal functions could affect the cellular functions of the HBECs. Protein expression studies on the cells could give an insight to associate lysosomal dysfunction on HBECs homeostasis. The aim of this study was to measure the cellular changes via the expression of several proteins such as Claudin-5, which is a tight junction protein; intracellular adhesion molecule 1 (ICAM-1), an inflammatory marker and endothelial nitric oxide synthase (eNOS), which provides nitric oxide (NO) for vasodilation. These components are important in maintaining homeostasis as the imbalance could lead to endothelial impairment linked brain related disorders such as neurodegenerative disease. Methods HBECs were treated with 10 mM ammonium chloride, which is a lysosome inhibitor for 1 h. The protein lysates were collected and subjected for ICAM-1 and Claudin-5 measurement by capillary immunoassay instrument, while eNOS by ELISA. Results Claudin-5 and ICAM-1 expression significantly increased (p Conclusions Inhibition of lysosome by the inhibitor increases protein expressions related with endothelial function.

Objectives Reference intervals of total cholesterol concentrations in plasma and of their fractions low-density lipoprotein (LDL)-, high-density lipoprotein (HDL)-and non-HDL concentrations are seldom studied with respect to the relevance of age and sex. Therefore, the effect of age and sex on the reference intervals was reinvestigated with 2 indirect procedures. Methods As an indirect approach, the truncated minimum chi-square method was applied. All analyses were performed by computer programs available. The script published on the homepage of the German Society of Clinical Chemistry and Laboratory Medicine (DGKL) allows to derive a continuous age dependency of reference intervals together with their confidence and equivalence limits. The results of this approach were compared with those obtained by an indirect method developed more recently, the refineR algorithm. Results In the present study, the upper reference limits of total cholesterol varied from 5.1 to 7.8 mmol/L (197–302 mg/dL) depending on various biological variables (as age, sex, inpatients versus outpatients). These upper limits increased with age. Differences between sexes can be neglected except for the age above 80 years. The pattern of reference limits of LDL cholesterol and non-HDL cholesterol paralleled those of total cholesterol. The reference limits of HDL cholesterol were higher in women than in men but were independent of age. Conclusions Reference limits for the concentrations of total cholesterol and their fractions LDL-, HDL-and non-HDL concentrations should be stratified for age and sex.

Objectives Collective intelligence, the “wisdom of the crowd,” seeks to improve the quality of judgments by aggregating multiple individual inputs. Here, we evaluate the success of collective intelligence strategies applied to probabilistic diagnostic judgments. Methods We compared the performance of individual and collective intelligence judgments on two series of clinical cases requiring probabilistic diagnostic assessments, or “forecasts”. We assessed the quality of forecasts using Brier scores, which compare forecasts to observed outcomes. Results On both sets of cases, the collective intelligence answers outperformed nearly every individual forecaster or team. The improved performance by collective intelligence was mediated by both improved resolution and calibration of probabilistic assessments. In a secondary analysis looking at the effect of varying number of individual inputs in collective intelligence answers from two different data sources, nearly identical curves were found in the two data sets showing 11–12% improvement when averaging two independent inputs, 15% improvement averaging four independent inputs, and small incremental improvements with further increases in number of individual inputs. Conclusions Our results suggest that the application of collective intelligence strategies to probabilistic diagnostic forecasts is a promising approach to improve diagnostic accuracy and reduce diagnostic error.

New millennium diagnostic criteria for acute myocardial infarction precipitated a revolutionary shift from an approach based primarily on electrocardiography and clinical symptoms to a strategy based on biomarkers, and preferably cardiac troponins (cTn) I and T. In the last 20 years, clinical recommendations have strengthened the role of cTn and led to the development of highly sensitive (hs-cTn) assays, which are now leading players in all current clinical practice guidelines. To optimize the clinical use of these hs-cTn assays, focus on their analytical aspects has become increasingly important, emphasizing the need for the establishment of suitable analytical performance by the definition and implementation of appropriate specifications. An accurate estimate of measurement uncertainty, together with the acquisition of the highest analytical quality when very low concentrations of hs-cTn are measured, are essential requirements and should represent a practical laboratory standard in assuring optimal clinical use. Additional goals for further improving the quality of laboratory information should be the establishment of robust data concerning biological variation of cTn and the resolution of practical challenges opposed to the harmonization of cTn I results obtained by differing commercial measuring systems.

Objectives The heme oxygenase-1 (HMOX1) gene is a very critical player in cell homeostasis and takes part in heme catabolism. The HMOX1 gene possesses antioxidant, antiapoptotic anti-inflammatory, and antithrombotic properties. This study aimed to identify the deleterious SNPs which may alter the functional and structural attributes of the HMOX1 protein. Methods Deleterious SNPs were predicted using Polyphen-1, SIFT Blink, Polyphen-2, I-MUTANT 2.0, PROVEAN, PANTHER, MAPP, SNAP, and PhD-SNP. The 3D structure of the native protein was modelled using ITASSER and validated using PROCHECK. Mutant structures were created through SWISS PDB Viewer. All structures were energy-minimized using GROMACS. Protein-protein interaction (PPI) network was done using STRING. Results Three deleterious SNPs (rs146227657, rs373577583, and rs138349040 corresponding to A88D, A131V, and A206E respectively) in the HMOX1 gene were predicted. The structural analysis revealed notable differences in the structural attributes of wild-type and mutant structures. Furthermore, a PPI network was generated for the HMOX1 gene which predicts its interaction with other crucial cellular signaling molecules. Conclusions Three reported SNPs (A88D, A131V, and A206E) were identified as highly deleterious in the HMOX1 coding region that can alter the protein secondary structure, protein stability, and its conservation. This paves a new way to study the phenotype of the HMOX1 gene and its correlating diseases.

Objectives Curriculum for clinical reasoning in the preclinical years is sparse and the COVID-19 pandemic heightened the need for virtual curriculums. Methods We developed, implemented and evaluated a virtual curriculum for preclinical students scaffolding key diagnostic reasoning concepts: dual process theory, diagnostic error, problem representation and illness scripts. Fifty-five second-year medical students participated in four 45-min virtual sessions led by one facilitator. Results The curriculum led to increased perceived understanding and increased confidence in diagnostic reasoning concepts and skills. Conclusions The virtual curriculum was effective in introducing diagnostic reasoning and was well-received by second-year medical students.

Proton pump inhibitors (PPIs) are widely used to suppress gastric acid secretion. Proton pumps belong to the family of ATPase and among them P-ATPase and V-ATPase types regulate intracellular as well as extracellular acid equilibrium. The main aim of the current survey is to present the existing literature putting forth the relation between cancer with both the use of PPIs and proton pumps from positive and negative aspects. To perform an objective study, various types of proton pumps and their relation to cancer have been taken into account. Up to date, the studies have been considered in the time range from 2011 to 2021 via various databases (PubMed, Scopus, and Google Scholar). H+/K+ ATPase, located within the gastric parietal cells, is one of the most important examples of P-ATPases. The findings of the literature review along with criticism were presented as decreased P-ATPase expression can be used as a marker for gastric cancer diagnosis whereas the association of the proton pump with cancer may be mainly due to V-ATPase. In conclusion, molecular, epidemiological, and bioinformatic studies are required to enlighten the subject.

Objectives Sex hormone binding globulin (SHBG) is a hormone binding protein which plays an important role in regulating the transport and availability of biologically active androgens and estradiol to target cells and used to calculate free testosterone concentrations. Methods A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed, featuring an albumin removal step followed by a tryptic digestion. After a reduction step with dithiothreitol and alkylation with iodoacetamide three signature peptides were used for the quantification of SHBG. Results The method enables the quantification of serum and plasma SHBG over the clinically relevant range of 200–20,000 ng/mL and was validated according to the most recent guidelines. The LC-MS/MS method correlates well with the Abbott Alinity immunoassay (R2>0.95), but the LC-MS/MS results are on average 16–17% lower than the immunoassay results, which is consistent for all three signature peptides. Conclusions The LC-MS/MS method which includes an albumin depletion step allows quantification of SHBG in serum and plasma without an immunocapture step at clinically relevant SHBG levels, thus contributing to better lab-to-lab consistency of results.

Objectives The WHO’s standardized measuring unit, “binding antibody units per milliliter (BAU/mL),” should allow the harmonization of quantitative results by different commercial Anti-SARS-CoV-2 immunoassays. However, multiple studies demonstrate inter-assay discrepancies. The antigenic changes of the Omicron variant affect the performance of Spike-specific immunoassays. This study evaluated the variation of quantitative Anti-SARS-CoV-2-Spike antibody measurements among 46, 50, and 44 laboratories in three rounds of a national external quality assessment (EQA) prior to and after the emergence of the Omicron variant in a diagnostic near-to-real-life setting. Methods We analyzed results reported by the EQA participant laboratories from single and sequential samples from SARS-CoV-2 convalescent, acutely infected, and vaccinated individuals, including samples obtained after primary and breakthrough infections with the Omicron variant. Results The three immunoassays most commonly used by the participants displayed a low intra-assay and inter-laboratory variation with excellent reproducibility using identical samples sent to the participants in duplicates. In contrast, the inter-assay variation was very high with all samples. Notably, the ratios of BAU/mL levels quantified by different immunoassays were not equal among all samples but differed between vaccination, past, and acute infection, including primary infection with the Omicron variant. The antibody kinetics measured in vaccinated individuals strongly depended on the applied immunoassay. Conclusions Measured BAU/mL levels are only inter-changeable among different laboratories when the same assay was used for their assessment. Highly variable ratios of BAU/mL quantifications among different immunoassays and infection stages argue against the usage of universal inter-assay conversion factors.

Objectives This study investigated the effect of appropriate pre-phlebotomy instructions on patients’ awareness of the need to fast, their fasting status at phlebotomy, and the measurement of specific biochemical analytes and indices. Methods While booking their phlebotomy appointments, two-hundred outpatients, with a wide range of pre-existing medical conditions, were recruited and randomly assigned to either control or intervention groups. The control group received no instructions while the intervention group was verbally instructed to fast for precisely 12 h prior to their appointment. Serum samples were collected from participants to quantify common biochemical analytes and serum indices, some of which were known to be influenced by fasting status, such as triglyceride and the lipaemic index. At the same appointment, participants completed a survey assessing their perception of, and adherence to, fasting requirements. Results In the intervention group, 99% responded that they had fasted before phlebotomy vs. 16% of controls. Subjects stated they fasted for 12 h in 51% of the intervention group and 7% of the controls. Median concentrations for potassium and total bilirubin were statistically, but not clinically, significantly different. In the study, a single patient in the intervention group was found to have a lipaemic sample. Conclusions Without instruction, it appears few patients will fast appropriately prior to blood collection. This study suggests that most patients recall and adhere to verbal instructions regarding fasting. Though many in the control group stated they did not fast, triglyceride concentration and lipaemia were not significantly different from the intervention group, and biochemical analyses appear unaffected by fasting status.

Total testing process in a clinical laboratory is designed to produce useful information for patients and clinicians. The changing landscape of healthcare industry forces clinical laboratory leaders to meet the needs of their stakeholders, maximize operational efficiency and improve overall quality of patient care at the same time. The increasing number of data produced force healthcare services industry to digital transformation. Digital transformation is a process of change which includes finding solutions to novel and unmet requirements of an industry by integrating information, computing, communication and connectivity technologies to minimize the number of low-value tasks and focus on high-value tasks. As the process of digital transformation includes not only the modernization of IT infrastructure but also a paradigm shift in perception of value creation and delivery to improve the quality and cost-effectiveness of laboratory operations in the long run, financial, managerial, and educational issues have been blocking the widespread implementation. Clinical laboratories are at the crossroads on the road to the future. Laboratories that fail to align themselves with data-driven practices will risk losing a competitive advantage. In this review, strategies for a successful digital transformation will be overviewed in the context of clinical laboratory settings.

Objectives The therapeutic antibody infliximab (IFX) has improved the life quality of numerous autoinflammatory disease patients. However, IFX can trigger the generation of anti-drug antibodies (ADA), whose optimal evaluation and management are currently subject of controversial discussions. We present two novel surface plasmon resonance (SPR) biosensor assays for therapeutic drug monitoring of IFX and characterization of ADA and investigated the diagnostic value of ADA binding properties. Methods IFX and ADA were quantified via developed SPR biosensor assays (IFXmon and ADAmon, respectively) and diagnostics-approved ELISA in sera from inflammatory bowel disease patients. Pre-analytic ADA enrichment with magnetic beads enabled analytical drug tolerance of the ADAmon assay. The dissociation ratio (DissR) as an index for ADA:IFX binding stability was calculated from the SPR sensorgrams of ADA quantification runs. Results IFX levels determined by IFXmon assay and ELISA showed high agreement, whereas ADA quantification concordance between ADAmon assay and ELISA was poor. In patients, DissR was predominantly constant over time and differed significantly between therapy outcomes. A DissR cut-off of 1.524 indicated undetectable IFX levels with 71.4% sensitivity and 88.9% specificity. Additionally, the SPR reference surface was exploited as serum-individual negative control to check result plausibility within multi-sample run sequences. Conclusions Overall, both SPR biosensor assays exhibited reliable quantitative performance with accuracies superior to their ELISA counterparts and precision inferior to ELISA only for ADAmon. DissR presented itself as promising ADA binding parameter and could contribute to both earlier and more tailored therapeutic decisions.

Laboratories and diagnostic departments are presiding over a massive amount of data they are failing to fully leverage it. Data is the new black gold of healthcare organizations and by extracting insights from it, laboratories could become true decision engines, able to drive action across healthcare. This opinion paper responds three fundamental questions: (1) Where are we (diagnostic parties)? Taking a look at the most significant trends and challenges in healthcare and shedding some light upon the status of diagnostics. (2) Where do we want to be? Reviewing the opportunities for digital health, its role in the healthcare of the future and providing inspiration about what success looks like. (3) What do we need to do? Explaining what Digital Health Solutions (DHS) from Abbott is doing in this regard. This will include information about how DHS can impact the Diagnosis Cycle and how to set a roadmap for laboratories and diagnostic organizations. Diagnosis Cycle means the different steps in the diagnosis process, from the beginning when a patient is seen by a clinician and some tests are ordered, until the results are reviewed by the clinician and the treatment, follow up or discharge is decided.

Objectives Automated sample delivery and laboratory acceptance systems (PTAS) may influence the hemolysis rate of blood samples due to g-forces, abrupt acceleration, and rapid deceleration. However, quantitative data regarding the rate of hemolysis in PTAS is limited. To fill this void, the effect of a pneumatic tube in combination with an acceptance system (PTAS) on the hemolysis rate was investigated in this study. Methods Lithium heparin plasma tubes were transported from different clinical departments to the hospital’s laboratory (a) by employees or (b) with an automated PTAS and analyzed for the presence of hemolysis based on a hemolysis index (HI) of >25. Hemolysis indices of 68.513 samples were retrieved from the laboratory information system before and after installation of the PTAS and were subjected to statistical analysis. Results A total of 32.614 samples were transported by employees, of which 3.815 samples (11.70%) were hemolytic, and 9.441 out of 35.899 samples delivered by PTAS (26.30%) were hemolytic. After the implementation of the PTAS, hemolysis rates increased in all departments. Conclusions Automated PTAS are associated with increased hemolysis rates. This has implications for routine patient management and should be considered for the transportation of samples used for the determination of hemolysis-sensitive laboratory parameters.

Direct-to-consumer (DTC) tests can be defined as any in-vitro diagnostic (IVD) test or, more broadly, any medical test using an IVD or medical device, that is marketed directly to consumers without involvement of a health care provider (HCP). Examples are pregnancy tests, alcohol breath tests, blood pressure measurements (medical device), coagulation tests (INR), self-monitoring of blood glucose, continuous glucose monitoring (medical device), HIV tests, HPV tests, SARS-CoV-2 antigen tests, or genetic tests. DTC tests fulfil various customer needs such as making rapid decisions (e.g. glucose monitoring for insulin dosing, SARS-CoV-2 antigen test, hormone test identifying fertile days, alcohol test), monitoring chronic conditions between consultations (e.g. diabetes, lipidaemia, hypertension), saving time and reducing consultations (e.g. INR, SARS-CoV-2 antigen test, blood pressure monitoring), screening for disease when no symptoms are present (e.g. occult blood, cholesterol, triglycerides, SARS-CoV2 antigen test), or maintaining privacy (e.g. pregnancy test, HIV test, HPV test, certain genetic tests). Further, DTC tests can reduce cost and expand access to care in countries with limited resources and can support healthcare systems in extraordinary circumstances such as a pandemic. Valid concerns about DTC testing need to be described, addressed and resolved with the help of authorities and regulators in collaboration with HCP and should not detract from the advantages DTC tests can provide. HCP should play a more prominent role in educating the public through mass media and social media on the proper use of DTC tests and help to pinpoint problem areas.

Objectives VEXAS syndrome is a newly described autoinflammatory disease associated with UBA1 somatic mutations and vacuolization of myeloid precursors. This disease possesses an increasingly broad spectrum, leading to an increase in the number of suspected cases. Its diagnosis via bone-marrow aspiration and UBA1-gene sequencing is time-consuming and expensive. This study aimed at analyzing peripheral leukocytes using deep learning approaches to predict VEXAS syndrome in comparison to differential diagnoses. Methods We compared leukocyte images from blood smears of three groups: participants with VEXAS syndrome (identified UBA1 mutation) (VEXAS); participants with features strongly suggestive of VEXAS syndrome but without UBA1 mutation (UBA1-WT); participants with a myelodysplastic syndrome and without clinical suspicion of VEXAS syndrome (MDS). To compare images of circulating leukocytes, we applied a two-step procedure. First, we used self-supervised contrastive learning to train convolutional neural networks to translate leukocyte images into lower-dimensional encodings. Then, we employed support vector machine to predict patients’ condition based on those leukocyte encodings. Results The VEXAS, UBA1-WT, and MDS groups included 3, 3, and 6 patients respectively. Analysis of 33,757 images of neutrophils and monocytes enabled us to distinguish VEXAS patients from both UBA1-WT and MDS patients, with mean ROC-AUCs ranging from 0.87 to 0.95. Conclusions Image analysis of blood smears via deep learning accurately distinguished neutrophils and monocytes drawn from patients with VEXAS syndrome from those of patients with similar clinical and/or biological features but without UBA1 mutation. Our findings offer a promising pathway to better screening for this disease.

Objectives This study investigated the feasibility and clinical value of using a novel, automated and high-throughput SARS-CoV-2 Interferon Gamma Release Assay (IGRA), combined with total anti-SARS-CoV-2 antibodies assessment, for evaluating the immune response after bivalent BNT162b2 vaccination. Methods A cohort of healthcare workers, who already underwent primary vaccination and boosting with monovalent BNT162b2 vaccine, received a booster dose of the new BNT162b2 bivalent formulation. Blood samples were taken immediately before vaccination (T0) and 1 month afterwards (T1). Humoral and cellular immunity were assayed with Roche Elecsys Anti-SARS-CoV-2 and Roche Elecsys IGRA SARS-CoV-2, respectively. Results The study population consisted of 51 subjects (median age: 43 years; 51% females). Total anti-SARS-CoV-2 antibodies and IGRA SARS-CoV-2 values increased at T1 from 9,050 to 25,000 BAU/mL (p Conclusions The bivalent BNT162b2 vaccine booster enhances humoral and cellular immunity against SARS-CoV-2, especially in recipients with lower baseline biological protection.

Whilst version 2 focussed on the professional conduct expected of a Specialist in Laboratory Medicine, version 3 builds on the responsibilities for ethical conduct from point of planning to point of care. Particular responsibilities that are outlined include: – The need for evidence when planning a new service, providing assurance that a new test does not do harm – Maintaining respect for patient confidentiality, their religious/ethnic beliefs, the need for informed consent to test, agreement on retrospective use of samples as part of governance envelopes in the pre-analytical phase – Ensuring respect for patient autonomy in the response to untoward results generated in the analytical phase – Supporting the safety of patients in the post-analytical phase through knowledge-based interpretation and presentation of results – The duty of candour to disclose and respond to error across the total testing process – Leading initiatives to harmonise and standardise pre-analytical, analytical and post-analytical phases to ensure more consistent clinical decision making with utilisation of demand management to ensure more equitable access to scarce resources – Working with emerging healthcare providers beyond the laboratory to ensure consistent application of high standards of clinical care In identifying opportunities for wider contributions to resolving ethical challenges across healthcare the need is also highlighted for more external quality assurance schemes and ethics-based quality indicators that span the total testing process.

Objectives Concentrations of pyridoxal 5′-phosphate (PLP) in serum and whole blood are routinely measured. The suitability of these markers in capturing vitamin B6 insufficiency is not well studied. Methods In 212 subjects, concentrations of PLP and thiamine pyrophosphate (TPP) were simultaneously measured in EDTA-whole blood using Chromsystems® (52052) method on HPLC devices. The whole blood PLP concentrations were compared to serum PLP concentrations measured using reagents from Immundiagnostik® (KC 2100). The whole blood TPP concentrations measured with the Chromsystems® (52052) were compared to those measured by the Chromsystems® (35000) method. Concentrations of homocysteine (tHcy) and cystathionine (Cys) were measured and used to judge the PLP methods. Results Serum PLP concentrations were on average 41% lower than whole blood PLP [mean (SD)=55.4 (83.0) vs. 131 (217) nmol/L]. Serum and whole blood PLP showed a strong correlation [Pearson correlation coefficient=0.724, p51 nmol/L) while 102 samples showed coherent results (reference group). The discrepancy group showed higher odds ratio for elevated tHcy >12.0 μmol/L compared to the reference group [OR (95% confidence intervals, CI)=2.1 (1.2–4.0)]. The OR (95% CI) of elevated Cys >300 nmol/L was 1.9 (1.0–3.5) in the discrepancy group compared to the reference group. TPP concentrations were 6% lower when using the Chromsystems®, 52052 compared to levels measured with Chromsystems®, 35000. Conclusions Serum and whole blood PLP concentrations disagree in a substantial number of samples. Serum PLP was better in reflecting elevated tHcy and Cys compared to whole blood PLP. Whole blood PLP underestimates the prevalence of vitamin B6 insufficiency. Methods of measuring TPP concentrations in whole blood were exchangeable.

The increase in the formation of reactive oxygen and reactive nitrogen species of endogenous or exogenous origin causes oxidative stress due to pro-oxidant and antioxidant imbalance that causes cellular damage in metabolism. This can increase inflammation of cells, apoptosis and necrosis, damage to DNA base damage, DNA and protein cross-links, lipid membrane peroxidation, and mitochondrial dysfunction. Antioxidants can be described as a system that protects biomolecules and the organism against the harmful effects of free radicals, reduces or repairs the damage done by reactive oxygen species (ROS) to the target molecule, and this is called antioxidant defense. It is known that the mechanisms caused by the increase in ROS resulting from oxidative stress are positively related to the pathology of many diseases such as cancer, metabolic syndrome, atherosclerosis, malaria, Alzheimer’s disease, rheumatoid arthritis, neurodegenerative diseases and preeclampsia.

Objectives Notch is a conserved pathway involved in cell-fate determination and homeostasis. Its dysregulation plays a role in poor prognosis and drug resistance in breast cancer. Targeting Notch signaling via inhibition of the gamma-secretase complex is in the spotlight of modern cancer treatments. Gamma-secretase inhibitors (GSI) have shown successful clinical activity in treating cancers, yet the possible resistance mechanism remains unstudied. Modeling the resistance and understanding culprit molecular mechanisms can improve GSI therapies. Accordingly, the aim of this study is to generate and analyze GSI-resistant breast cancer cells. Methods Gradually increasing doses of DAPT, a well-known GSI, were applied to MCF-7 breast cancer cell lines to generate resistance. Cell viability, migration and gene expressions were assessed by MTT, wound healing and qRT-PCR analyses. Results DAPT-resistant MCF-7 cells exhibited abnormal expression of Notch receptors, Notch targets (HES1, HES5, HEY1), and epithelial-mesenchymal transition (EMT) markers (E-cadherin, ZO-1, SNAIL2, N-cadherin) to overcome the continuous increase in DAPT toxicity by increased migration through mesenchymal transition. Conclusions This study prospects into the role of EMT in the potential resistance mechanism against DAPT treatment for breast cancer cells. Complementary targeting of EMT should be investigated further for a possible effect to potentiate DAPT’s anti-cancer effects.

Objectives In the current study, we synergistically evaluated vascular endothelial growth factor (VEGF) gene expression levels and signal peptide-CUB-EGF domain-containing protein 1 (SCUBE1) gene expression levels in diabetic patients without retinopathy, non-proliferative diabetic retinopathy (NPDR), and proliferative diabetic retinopathy (PDR). Methods 94 blood samples from 26 healthy controls, 29 non-DR, 22 NPDR, and 17 PDR patients were collected in sterile EDTA tubes. Total RNA was obtained from these samples without waiting and then converted to cDNA. The expression levels of the VEGF and SCUBE1 genes were determined by quantitative real-time polymerase chain reaction (qPCR). Results SCUBE1 gene expression levels were 2.15 (p=0.015), 1.75 (p=0.799), 2.37 (p=0.037) times higher, and VEGF gene expression levels were 1.71 (p=0.023), 1.75 (p=0.012), 1.85 (p=0.031) times higher in the non-DR, NPDR, and PDR groups compared to the control group, respectively. VEGF gene expression levels were significantly higher in participants with HbA1c levels ≥5.7% compared to those with Conclusions As a result, SCUBE1 gene expression levels are higher than VEGF gene expression levels, especially in the PDR group. Therefore, SCUBE1 may contribute to the pathology of DR just like VEGF by generating angiogenesis. However, we believe there is a need for experimental animal model studies with DR examining SCUBE1 gene expression levels in tissue samples.

Objectives This study aims to develop a novel library preparation method, plasma to library express technology (PLET), to construct next-generation sequencing (NGS) libraries directly from plasma without cell-free DNA (cfDNA) isolation. Methods Peripheral blood samples (600) were obtained from a retrospective cohort of 300 pregnant women prior to invasive diagnostic testing. The samples were subsequently distributed between library preparation methodologies, with 300 samples prepared by PLET and 300 by conventional methods for non-invasive prenatal testing (NIPT) to screen for common trisomies using low-pass whole genome next generation sequencing. Results NIPT conducted on PLET libraries demonstrated comparable metrics to libraries prepared using conventional methods, including 100% sensitivity and specificity. Conclusions Our study demonstrates the potential utility of PLET in the clinical setting and highlights its significant advantages, including dramatically reduced process complexity and markedly decreased turnaround time.

Objectives Clinical practice guidelines endorse the stratification of prostate cancer (PCa) risk according to individual total prostate-specific antigen (tPSA) values and age to enhance the individual risk-benefit ratio. We defined two nomograms to predict the individual risk of high and low grade PCa by combining the assay of tPSA and %free/tPSA (%f/tPSA) in patients with a pre-biopsy tPSA between 2 and 10 μg/L. Methods The study cohort consisted of 662 patients that had fPSA, tPSA, and a biopsy performed (41.3% with a final diagnosis of PCa). Logistic regression including age, tPSA and %f/tPSA was used to model the probability of having high or low grade cancer by defining 3 outcome levels: no PCa, low grade (International Society of Urological Pathology grade, ISUP Results The nomogram identifying patients with: (a) high vs. those with low grade PCa and without the disease showed a good discriminating capability (∼80%), but the calibration showed a risk of underestimation for predictive probabilities >30% (a considerable critical threshold of risk), (b) ISUP50%. In ISUP 5 a possible loss of PSA immunoreactivity has been observed. Conclusions The estimated risk of high or low grade PCa by the nomograms may be of aid in the decision-making process, in particular in the case of critical comorbidities and when the digital rectal examinations are inconclusive. The improved characterization of the risk of ISUP≥3 might enhance the use for magnetic resonance imaging in this setting.

Objectives The determination of assay-dependent upper and lower reference limits (URL, LRL) of free triiodothyronine (FT3), free thyroxine (FT4), and thyroid stimulating hormone (TSH) during childhood and adolescence, is challenging. Methods Thyroid hormones were measured via the Abbott Alinity system in 502 euthyroid children partitioned in the following age groups: ≤2, 2.1–10, and 10.1–18 years. The 97.5th and 2.5th percentiles (URL and LRL) were derived according to CLSI EP28- A3c guidelines. Quantile regression models were used to assess: (a) 90% confidence intervals of the URL and LRL, (b) the effect of age on URL and LRL within each age class and on overall age range, (c) the difference between the URLs and LRLs estimated for each age partition with an estimate of the confidence interval divided by the reference interval being derived (CI/RI). Results The CI/RI for the LRLs are smaller as compared to the URLs, except for FT4 for the 2.1–10 years age group. Considering the CI/RI and the overlap between CIs across the three age groups, one single LRL might be considered for TSH, FT3 and FT4 between 0 and 18 years. However, for the URL, there was a noticeable decrease in the URL over the 3 age groups for all three biomarkers, with there being no overlap in CIs for the URL between the ≤2 vs. the 10.1–19 years age groups. Conclusions A common LRL for TSH, FT4 and FT3 for patients aged ≤18 years may be utilized when these biomarkers are measured with the Alinity system. For the URLs the use of age-specific URLs for these biomarkers is recommended.

Objectives Laboratory diagnostic services are essential to drive evidence-based treatment decisions, manage outbreaks, and provide population-level data. Many low- and middle-income countries (LMICs) lack sufficient diagnostic capacity, often further exacerbated in conflict-affected areas. This project assessed laboratory services in conflict-affected LMICs to understand gaps and opportunities for improving laboratory capacity. Methods The World Health Organization Laboratory Assessment Tool Facility Questionnaire (WHO Laboratory Tool) and Stepwise Laboratory Improvement Process Towards Accreditation (SLIPTA) checklist were used to assess five laboratories in Eastern Democratic Republic of the Congo (DRC) and five in Gaza, Palestine. Total scores and percentage outcomes by indicator were calculated. Results Average WHO Laboratory Tool score across all facilities was 41% (range 32–50%) in DRC and 78% (range 72–84%) in Gaza. Lowest scoring indicators in DRC were Biorisk management (13%, range 8–21%), Documentation (14%, range 6–21%), and in Gaza, were Facilities (59%, range 46–75%) and Documentation (60%, range 44–76%). Highest scoring indicators in DRC were Facilities (70%, range 45–83%) and Data and Information Management (61%, range 38–80%), and in Gaza were Data Information and Management (96%) and Public Health Function (91%, range 88–94%). In DRC, no laboratory achieved a SLIPTA star rating. In Gaza, two laboratories had a 3-star SLIPTA rating, one had a 2-star rating and two had a 1-star rating. Conclusions Laboratory systems in conflict-affected LMICs have significant gaps. Implementating improvement strategies in such settings may be especially challenging.

Objectives Confounding factors, including sex, age, and renal dysfunction, affect high-sensitivity cardiac troponin T (hs-cTnT) concentrations and the acute myocardial infarction (AMI) diagnosis. This study assessed the effects of these confounders through logistic regression models and evaluated the diagnostic performance of an optimized, integrated prediction model. Methods This retrospective study included a primary derivation cohort of 18,022 emergency department (ED) patients at a US medical center and a validation cohort of 890 ED patients at a Canadian medical center. Hs-cTnT was measured with 0/3 h sampling. The primary outcome was index AMI diagnosis. Logistic regression models were optimized to predict AMI using delta hs-cTnT and its confounders as covariates. The diagnostic performance of model cutoffs was compared to that of the hs-cTnT delta thresholds. Serial logistic regressions were carried out to evaluate the relationship between covariates. Results The area under the curve of the best-fitted model was 0.95. The model achieved a 90.0% diagnostic accuracy in the validation cohort. The optimal model cutoff yielded comparable performance (90.5% accuracy) to the optimal sex-specific delta thresholds (90.3% accuracy), with 95.8% agreement between the two diagnostic methods. Serial logistic regressions revealed that delta hs-cTnT played a more predominant role in AMI prediction than its confounders, among which sex is more predictive of AMI (total effect coefficient 1.04) than age (total effect coefficient 0.05) and eGFR (total effect coefficient −0.008). Conclusions The integrated prediction model incorporating confounding factors does not outperform hs-cTnT delta thresholds. Sex-specific hs-cTnT delta thresholds remain to provide the highest diagnostic accuracy.

In accordance with all the most recent international guidelines, the variation of circulating levels of cardiac troponins I and T, measured with high-sensitivity methods (hs-cTnI and hs-cTnT), should be used for the detection of acute myocardial injury. Recent experimental and clinical evidences have demonstrated that the evaluation of hs-cTnI and hs-cTnT variations is particularly relevant: a) for the differential diagnosis of Acute Coronary Syndromes (ACS) in patients admitted to the Emergency Department (ED); b) for the evaluation of cardiovascular risk in patients undergoing major cardiac or non-cardiac surgery, and in asymptomatic subjects of the general population aged >55 years and with co-morbidities; c) for the evaluation of cardiotoxicity caused by administration of some chemotherapy drugs in patients with malignant tumors. The aim of this document is to discuss the fundamental statistical and biological considerations on the intraindividual variability of hs-cTnI and hs-cTnT over time in the same individual. Firstly, it will be discussed in detail as the variations of circulating levels strictly depend not only on the analytical error of the method used but also on the intra-individual variability of the biomarker. Afterwards, the pathophysiological interpretation and the clinical relevance of the determination of the variability of the hs-cTnI and hs-cTnT values ​​ in patients with specific clinical conditions are discussed. Finally, the evaluation over time of the variation in circulating levels of hs-cTnI and hs-cTnT is proposed for a more accurate estimation of cardiovascular risk in asymptomatic subjects from the general population.

Objectives Amphotericin B (AmB) is the gold standard for treating invasive fungal infections. New liposomal-containing AmB formulations have been developed to improve efficacy and tolerability. Serum/plasma C-reactive protein (CRP) values are widely used for monitoring infections and inflammation. CRP shows a high affinity to phosphocholine and it aggregates structures bearing this ligand, e.g. phosphocholine-containing liposomes. Therefore, we studied the interaction between CRP and phosphocholine-containing liposomal AmB preparations in vivo and in vitro. Methods CRP was prepared by affinity chromatography. Liposomal AmB (L-AmB, AmBisome®) was spiked (final concentrations of L-AmB: 150 mg/L) to CRP-containing serum (final CRP concentration: 300 mg/L). Following the addition of L-AmB, complex formation was monitored turbidimetrically. The size of CRP-L-AmB complexes was assessed using gel filtration. CRP was monitored in patients receiving either L-Amb or AmB lipid complex (ABLC). Results Following addition of L-AmB to CRP-containing plasma, turbidimetry showed an increase in absorbance. These results were confirmed by gel permeation chromatography. Similarly, in vivo effects were observed following intravenous administration of AmBisome®: a decline in CRP values was observed. In patients receiving L-Amb, decline of CRP concentration was faster than in patients receiving ABLC. Conclusions In vitro experiments are suggestive of a complexation between CRP and liposomes in plasma. Interpretation of CRP values following administration of AmBisome® might be impaired due to this complexation. In vivo formation of complexes between liposomes and CRP might contribute, or even lead, to intravascular microembolisation. Similar effects have been described following the administration of Intralipid® and other phosphocholine-containing liposomes.

Objectives The aim of this study was to evaluate the impact of long-term sample storage on the concentrations of neopterin and neurofilament light (Nfl) in cerebrospinal fluid (CSF) samples. These are useful markers of neuroinflammation and neuronal damage and have been applied as biomarkers for several neurological diseases. However, different pre-analytical variables have potential to influence results. Methods Twenty-one CSF samples donated by patients with HTLV-1-associated myelopathy (HAM) and stored for up to 11 years at −80 °C were retested after three-years for neopterin (n=10) and Nfl (n=11) by ELISA. Results There was a strong correlation between the paired results (r>0.98, p Conclusions Storing CSF samples at −80 °C appears not to impact the quantification of neopterin and Nfl allowing confidence in the reporting of archived samples.

Background Laboratory medicine has reached the era where promises of artificial intelligence and machine learning (AI/ML) seem palpable. Currently, the primary responsibility for risk-benefit assessment in clinical practice resides with the medical director. Unfortunately, there is no tool or concept that enables diagnostic quality assessment for the various potential AI/ML applications. Specifically, we noted that an operational definition of laboratory diagnostic quality – for the specific purpose of assessing AI/ML improvements – is currently missing. Methods A session at the 3rd Strategic Conference of the European Federation of Laboratory Medicine in 2022 on “AI in the Laboratory of the Future” prompted an expert roundtable discussion. Here we present a conceptual diagnostic quality framework for the specific purpose of assessing AI/ML implementations. Results The presented framework is termed diagnostic quality model (DQM) and distinguishes AI/ML improvements at the test, procedure, laboratory, or healthcare ecosystem level. The operational definition illustrates the nested relationship among these levels. The model can help to define relevant objectives for implementation and how levels come together to form coherent diagnostics. The affected levels are referred to as scope and we provide a rubric to quantify AI/ML improvements while complying with existing, mandated regulatory standards. We present 4 relevant clinical scenarios including multi-modal diagnostics and compare the model to existing quality management systems. Conclusions A diagnostic quality model is essential to navigate the complexities of clinical AI/ML implementations. The presented diagnostic quality framework can help to specify and communicate the key implications of AI/ML solutions in laboratory diagnostics.

Objectives The primary objective was to determine levels of C3-epi-25(OH)D in very low birth weight infants. The secondary objective was to evaluate the possible influence of preterm birth, intrauterine growth restriction (IUGR), and season of birth on the production of C3-epimers. Methods A total of 127 infants with birth weight less than 1,500 g met the inclusion criteria of the study. We examined 25-hydroxyvitamin-D [25(OH)D] levels and C3-epi-25(OH)D in maternal serum before labor, and in cord blood and infants’ serum on days 14 and 28, and at discharge. Results The mean levels (±SD) of C3-epi-25(OH)D of the cord, on day 14, on day 28, and at discharge were 2.2 (2.9), 7.7 (5.5), 11.7 (7.6) and 14.9 (11.7) nmol/L respectively. The proportion of total 25(OH)D as the C3-epimer was 6.9% (cord), 16.3% (day 14), 22.4% (day 28) and 23.3% (discharge). A statistically significant correlation between 25(OH)D and C3-epi-25(OH)D can be demonstrated from birth. The severity of immaturity and IUGR did not affect the production of C3-epimers. In summer/autumn vs. winter/spring, the mean (SD) percentage of total 25(OH)D as the C3-epimer significantly differs only in maternal serum samples and umbilical cord samples (p value Conclusions The production of C3-epi-25(OH)D is functional even in the most immature newborns, has fetal origins, and is largely dependent on circulating 25(OH)D. At the end of the first month of life, C3-epimers make up more than 20% of 25(OH)D.

Objectives Establishing direct reference intervals for pediatric patients is a costly, challenging, and time-consuming enterprise. Indirectly established reference intervals can help to ameliorate this situation. It was our objective to establish population-specific reference intervals for automated white blood cell differentials via data mining and non-parametric percentile method. Methods Blood counts and automated white blood cell differentials of patients aged 0 days to 18 years, performed from the 1st of January 2018 until the 30th of June 2022, were identified in our laboratory information system. Reference intervals were established in accordance with IFCC and CLSI recommendations as well as the propositions by Haeckel et al. Results Initially, 47,173 blood counts on our SYSMEX XN-9000 were identified. 11,707 data sets were excluded, leaving 35,466 sample sets for analysis. Of these, 17,616 contained automated white blood cell differentials. Due to insufficient patient numbers, no reference intervals for automated white blood cell differentials could be established for children aged Conclusions The combination of non-parametric percentile method and the propositions by Haeckel et al. utilizing conscientious data mining appears to be potent alternative to direct reference interval determination.

Objectives Allogeneic hematopoietic cell transplantation (HCT) is associated with acute graft-vs.-host disease (aGVHD). The presented study applied a novel multiplex antibody-based proximity extension assay (PEA) proteomic platform that can detect thousands of serum proteins simultaneously for the identification of potential biomarkers of aGVHD. Methods Serum samples from 28 patients who underwent allogeneic HCT for acute myeloid leukemia (AML) were analyzed; 17 were diagnosed with grade II–IV aGVHD while 11 patients were not. Samples collected on day −6, day 0, +14, +30, +60 and +90 post-HCT were analyzed for the relative concentrations of 552 proteins. The concentration of each protein from baseline to the closest time point before onset of aGVHD, or to the latest time point in control patients, was documented. Results Individualized analysis identified 26 proteins demonstrating ≥3-fold increase at aGVHD onset compared to baseline, eliminating proteins with a similar increase in controls. Another approach used paired t-testing and logistic regression that identified a four-marker panel, including SLAMF7, IL-1ra, BTN3A2 and DAB2, where individual log-likelihood ratios ranged from 3.99 to 8.15 (logistic regression, p=0.004–0.046). When combined, the four-marker panel demonstrated an area under the curve (AUC) of 0.90 (95% CI: 0.78–1.00; p=0.0006) with high negative predictive value of 81.8% and positive predictive value of 86.7%. All four markers play a physiological role in immune regulation. Among these, three were also present in the individualized analysis (SLAMF7, IL-1ra and BTN3A2). Conclusions We conclude that serum proteins identified using multiplex proteomics, particularly SLAMF7, IL-1ra, BTN3A2 and DAB2, may potentially predict aGVHD.

Precision Medicine is a reality in selected medical areas, as oncology, or in excellent healthcare structures, but it is still far to reach million patients who could benefit from this medical concept. Here, we sought to highlight how the time is ripe to achieve horizontal delivery to a significant larger audience of patients, represented by the poly-treated patients. Combination therapies are frequent (especially in the elderly, to treat comorbidities) and are related to decreased drug safety and efficacy, disease’s exacerbation, additional treatments, hospitalization. But the recent development and validation of bioinformatic tools, aimed to automatic evaluation and optimization of poly-therapies, according to the unique individual characteristics (including genotype), is ready to change the daily approach to pharmacological prescription.

Objectives To describe a high-sensitivity SARS-CoV-2 antigen test that is based on the fully automated light-initiated chemiluminescent immunoassay (LiCA®), and to validate its analytical characteristics and clinical agreement on detecting SARS-CoV-2 infection against the reference molecular test. Methods Analytical performance was validated and detection limits were determined using different types of nucleocapsid protein samples. 798-pair anterior nasal swab specimens were collected from hospitalized patients and asymptomatic screening individuals. Agreement between LiCA® antigen and real-time reverse transcription polymerase chain reaction (rRT-PCR) was evaluated. Results Repeatability and within-lab precision were 1.6–2.3%. The C5∼C95 interval was −5.1–4.6% away from C50. Detection limits in average (SD) were 325 (±141) U/mL on the national reference panel, 0.07 (±0.04) TCID50/mL on active viral cultures, 0.27 (±0.09) pg/mL on recombinant nucleocapsid proteins and 1.07 (±1.01) TCID50/mL on inactivated viral suspensions, respectively. LiCA detected a median of 374-fold (IQR 137–643) lower levels of the viral antigen than comparative rapid tests. As reference to the rRT-PCR method, overall sensitivity and specificity were determined to be 97.5% (91.4–99.7%) and 99.9% (99.2–100%), respectively. Total agreement between both methods was 99.6% (98.7–99.9%) with Cohen’s kappa 0.98 (0.96–1). A positive detection rate of 100% (95.4–100%) was obtained as Ct≤37.8. Conclusions The LiCA® system provides an exceptionally high-sensitivity and fully automated platform for the detection of the SARS-CoV-2 antigen in nasal swabs. The assay may have high potential use for large-scale population screening and surveillance of COVID-19 as an alternative to the rRT-PCR test.

This tutorial shows how to perform a meta-analysis of diagnostic test accuracy studies (DTA) based on a 2 × 2 table available for each included primary study. First, univariate methods for meta-analysis of sensitivity and specificity are presented. Then the use of univariate logistic regression models with and without random effects for e.g. sensitivity is described. Diagnostic odds ratios (DOR) are then introduced to combine sensitivity and specificity into one single measure and to assess publication bias. Finally, bivariate random effects models using the exact binomial likelihood to describe within-study variability and a normal distribution to describe between-study variability are presented as the method of choice. Based on this model summary receiver operating characteristic (sROC) curves are constructed using a regression model logit-true positive rate (TPR) over logit-false positive rate (FPR). Also it is demonstrated how to perform the necessary calculations with the freely available software R. As an example a meta-analysis of DTA studies using Procalcitonin as a diagnostic marker for sepsis is presented.

Objectives The research was conducted as a descriptive study to evaluate the practices and knowledge levels of midwives and nurses in the preanalytical phase of newborn screening tests. Methods The sample of the study consisted of 233 midwives and nurses working in 90 primary healthcare centers in three major districts of Istanbul. The practices and knowledge levels of the participants in the preanalytical phase of blood sampling were evaluated with the Preanalytical Phase Evaluation Form [PPEF]. Results It was determined that only 43.3% of the participants comforted the baby before taking the blood sample, and 61.8% paid attention to the temperature of the heel. Furthermore, 56.2% continued to fill the same circle on the screening card by squeezing the heel due to inadequate blood, 62.7% ensured the blood completely soaked through the front and back of the card, and 36.1% used both sides of the card to fill the circles. Only 53.6% of the participants stored the dried blood samples in the fridge. The mean PPEF knowledge score of the participants was 14.64 ± 3.40. There were statistically significant differences in the knowledge scores of midwives and nurses according to age, educational level, and working year (p Conclusions In the study, it was determined that the practices of nurses and midwives in the preanalytical phase were not at a good level. In particular, it is recommended that nurses and midwives who are younger, have a lower educational level, and work fewer years be supervised and supported with training.

Objectives The aim was to evaluate the stability of serum bicarbonate at room temperature, depending on time to centrifugation and air exposure. Methods Stability study was conducted in the laboratory of Clinical Hospital Centre Rijeka, Croatia in January-February 2022. Nine samples from 10 volunteers were collected in clot activator gel tubes (Greiner Bio-One). Bicarbonate was measured on Beckman Coulter AU480 (Beckman Coulter, Brea, USA). Three tubes were left at room temperature for 30 min, three tubes for 2 h, three tubes for 4 h until centrifugation. First tube from first group (baseline) was measured immediately after centrifugation. Other measurements were expressed as percentage deviation (PD%) from baseline. First tube was remeasured after 1 and 2 h (OT_0h_1h; OT_0h_2h). Second and third tubes were opened 1 and 2 h after centrifugation (C_0h_1h; C_0h_2h). Second group of tubes was processed the same way with 2-hour centrifugation delay (WB_2h; OT_2h_1h; OT_2h_2h; C_2h_1h; C_2h_2h), and third group with 4-hour delay (WB_4h; OT_4h_1h; OT_4h_2h; C_4h_1h; C_4h_2h). PD% was compared to Maximum Permissible Difference (MPD=5.69%). MedCalc statistical software was used (MedCalc, Ostend, Belgium). Results Bicarbonate baseline mean value (range) was 27.3 (23.4–29.6) mmol/L. Obtained PD% (95%CI) were: C_0h_1h 0.46 (−1.21, 2.12); C_0h_2h 0.18 (−2.22, 2.57); OT_0h_1h −6.46 (−7.57, −5.36); OT_0h_2h −10.67 (−12.13, −9.21); WB_2h −0.15 (−2.04, 1.74); C_2h_1h 0.01 (−1.52, 1.54); C_2h_2h −0.40 (−2.65, 1.85); OT_2h_1h −5.43 (−7.30, −3.55); OT_2h_2h −11.32 (−13.57, −9.07); WB_4h −0.85 (−3.28, 1.58); C_4h_1h −2.52 (−4.93, 0.11); C_4h_2h −3.02 (−5.62, 0.43); OT_4h_1h −7.34 (−9.64, −5.05); OT_4h_2h −11.85 (−14.38, −9.33). Conclusions Serum bicarbonate is stable for 4 h in closed uncentrifuged tubes, another 2 h in closed tubes after centrifugation, and is unstable within 1 h in opened tube.